Work handling apparatus

ABSTRACT

In a work handling apparatus, a work engaging member which holds the workpiece is raised or lowered by means such as a cable hoist. Rotational movement of the work engaging member is effected by raising the work engaging member to engage a means for transmitting rotational movement such as a tubular shaft mounted for rotation. The work engaging member is rotatably mounted on the cable so that the tubular shaft can be turned without twisting the cable.

I United States Patent 1191 1111 3,738,521

Long, III June 12, 1973 4 WORK HANDLING APPARATUS FOREIGN PATENTS OR APPLICATIONS lhvehtori $3 Long, Hagerstown, 1,042,557 9/1966 Great Britain 254 173 R [73] Assignee: The Carborundum Company, Primary Examiner-Gerald Forlenza Niagara Falls, Assistant Examiner-George F. Abraham Attorney-David E. Dougherty and Robert E. [22] Filed: Jan. 3, 1972 Walter et aL [21] Appl. No.: 214,667 [57] ABSTRACT In a work handling apparatus, a work engaging member 52 U.S. c1. 214/658, 212/18, 212/30, which holds the workpiece is raised Or lowered y 294 32 means such as a cable hoist. Rotational movement of 51 Int. Cl B65h 5/12 the Work engaging member is effected y raising the [58] Field of Search 212/18, 30, 31, 71; work engaging member to engage a means transmit- 254 173 214 BB, 1 1 5g; 294 32 ting rotational movement such as a tubular shaft mounted for rotation. The work engaging member is 5 References Cited rotatably mounted on the cable so that the tubular shaft UNITED STATES PATENTS can be turned without twisting the cable.

3,495,720 2 1970 Mann 214 1 BA 10 Claims, 8 Drawing Figures trill/1111111157 PAIENIEU m a 2 ms SIIHZN I PATENIEB Jul 2 WORK HANDLING APPARATUS BACKGROUND OF THE INVENTION The present invention relates to apparatus for handling work and in particular work carriers that can be used for holding and transporting workpieces which are subject to a cleaning action such as by abrasive throwing wheels.

Various work carriers exist for various purposes. One particularly advantageous carrier is illustrated and described in U.S. pat. No. 3,495,720 which includes a self-powered trolley and a work engaging member capable of turning work in a treating cabinet. However, this type of carrier and others of the prior art require the aid of fork lift mechanisms, elevating systems from the floor line, or auxiliary powered hoist systems located adjacent to the work carriers to raise the work to the level of the work engaging member on the work carrier. Although this is effective in handling the work, considerable time and danger do exist in the transfer of work from a lifting apparatus to the work engaging unit of the work carrier.

SUMMARY OF THE INVENTION According to the present invention, there is provided a work handling apparatus comprising a frame, a work engaging member adapted to hold the workpiece, means on said frame for raising and lowering said work engaging member, said work engaging member being supported by said raising and lowering means for rotational movement about a substantially vertical axis, means supported by said frame for transmitting rotational movement to said work engaging member, said raising and lowering means being adapted to move said work engaging member to a raised position to effect engagement of said work engaging member with said transmitting means to rotate said work engaging member.

According to the present invention the frame can be a trolley, boom or other suitable support.

The present invention obviates one or more of the deficiencies of work handlers of the prior art. By having the means for raising and lowering the work of the present invention as an integral part of the supporting frame or work carrier, the hazards of transferring work are reduced. Furthermore, when the work engaging member is in engagement with the transmitting means such as a shaft, a rigid support is provided that prevents work from swaying during processing. When the work engaging member is raised or lowered by a cable hoist, this invention eliminates any undue strain placed on the cable due to twisting due to a rotatable mounting of the work engaging member on the cable.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic plane view of an arrangement including the work carrier of the present invention;

FIG. 2 is a side elevational view showing a portion of the work carrier of the present invention in section;

FIG. 3 is an end elevational view along section 33 of FIG. 2;

FIG. 4 is a side elevational view of the work carrier of the present invention;

FIG. 5 is a side elevational view of the work carrier showing the work engaging member is a lowered position;

FIG. 6 is a side elevational view of another embodiment of the work carrier of the present invention;

FIG. 7 is a side elevational view in section showing the detail of a means for stopping the hoist; and

FIG. 8 is a side elevational view of a jib boom of the present invention.

DETAILED DESCRIPTION FIG. 1 shows a general arrangement which includes a load station, a blast cleaning or treating station 11 and an unload station. The stations are interconnected by means of an overhead rail 13. It is on this rail 13 that the work carrier 15 is supported and pulled in a forward direction by any suitable translatory drive means such as a power operated tractor 17. A sprocket chain assembly 19 is provided at the blasting station 11 to rotate the work.

FIG. 4 is a side elevational view of the work carrier 15 of the present invention. As indicated therein the carrier 15 includes a pair of wheels 21 which are supported on a rail 13 and are pulled by the tractor l7 schematically shown in FIG. 1. It is to be understood that a single tractor 17 may be provided for each work carrier 15 or as shown in FIG. 1 a plurality of work carriers 15 may be interconnected with a group of such work carriers 15 moved by a single tractor 17.

Referring again to FIG. 4, a support or housing 25 is supported by wheels 21 with a tubular shaft or spindle casing 27 extending therefrom. The blasting station 11 may be of a suitable construction and may include a treating chamber having a pair of rubber lips 31 at its upper end which are open by a plow 29 whereby the lips 31 and plow 29 form a traveling seal. This type of seal is described in greater detail in US. Pat. No. 3,418,756. The-blasting station 11 can be of a type including a plurality of centrifugal throwing wheels which may be arranged at different elevations to thoroughly clean'the workpiece in a conventional manner.

The tubular shaft 27 is mounted on the housing 25 for rotation. The upper end of the shaft projects through an opening 33 in the floor of the housing 25. Suitable bearings 35 can be provided between a cap 37 on the end of the shaft 27 and the floor of the housing 25 to provide for a frictionless rotation of the shaft 27. The cap 37, bearings 35 and housing floor 25 bear the work load while permitting rotation of the shaft 27.

A lower housing or lower portion 39 of the housing 25 is cylindrically shaped and coaxial with the shaft 27. A pair of spaced bearing assemblies 41, one located at each end of the lower housing 39., is provided between the shaft 27 and the lower housing 39 for maintaining substantially vertical alignment of the shaft 27 while permitting rotation thereof. Intermediate the spaced bearing assemblies 41, a sprocket or gear 43 is secured to the shaft 27. An opening in the cylindrical wall of the lower housing 39 exposes the sprocket teeth for engagement. Suitable means are provided for rotating the tubular shaft 27, one such means is illustrated in FIG. 1. When the work is ina blasting station 11, the sprocket chain assembly 19 engages the sprocket 43 to cause rotation of the sprocket 43 and the shaft 27 which transmits the rotational movement to facilitate cleaning thereof.

Suitable means are provided for selectively engaging and disengaging the sprocket 43 with the sprocket chain assembly 19 without causing any interference to the tractor 17. This arrangement includes a chain trained about a pair of sprockets, one sprocket is driven by a suitable drive while the other sprocket is mounted for movement toward and away from the work carrier 15. The arrival of the tractor 17 at the blasting station 11 operates causing the sprocket chain assembly 19 to move into engagement with the sprocket 43. Thus, the work may be turned about a substantially vertical axis for obtaining complete cleaning thereof. Although the chain sprocket assembly 19 is external to the work carrier 15, means such as a motor with a gear drive can be mounted directly on the work carrier to effect the rotation of the tubular shaft 27.

A cable 45 which passes through the center opening in the shaft 27 is provided for raising and lowering a workpiece. One end of the cable 45 is secured to a suitable hoist arrangement 47 mounted on the housing 25. The hoist arrangement 47 includes a motor 49 which drives a drum 51 having the cable 45 attached thereto. As the motor 49 is actuated by suitable controls, the cable 45 either winds or unwinds on the drum 51 causing a workpiece to be raised or lowered. The cable 45 is trained around a suitable pulley 53 mounted for rotation above the opening in the tubular shaft 27 so as to prevent excessive wear of the cable 45 due to-contact with the shaft 27. Since the hoist arrangement 47 is used in conjunction with a self-propelled carrier 15, a voltage source is readily available in the form of an external source through a bus bar 55. Through the use of limit switches (not shown) at the blasting station 11, the hoist arrangement 47 can be made to operate either manually or automatically.

It is intended that the term cable as used herein include chains, lines, ropes or other flexible or inflexible means suitable for supporting the work engaging member 57 for vertical movement.

As illustrated in FIG. 2, a lower portion of the cable 45 extends exterior to the shaft 27 at the bottom end thereof. A work engaging member 57 which is adapted to engage the lower end of the tubular shaft 27 is rotatably mounted to the lower portion of the cable 45 extending through the shaft 27 so as to permit rotation of the workpiece without twisting the cable 45 when the work engaging member 57 is in engagement with the shaft 27. The work engaging member 57 includes a conical housing 59 that tapers inwardly and upwardly and has a central axial opening 60. Suitable bearing assemblies 61 are provided within the opening 60 between the inner surface of the conical housing 59 and the cable 45. As illustrated in FIG. 2 in detail, the cable 45 includes an outer cylindrical sheath 65 rigidly secured thereto. The pair of spaced bearing assemblies 61 are mounted between outwardly projecting collar 75 mounted securely to the sheath 65 and an end cap 67. The outer races of the respective bearing assemblies 61 are in contact with the inside surface of the conical housing 59. A sleeve 69 fits within a groove in the axial opening 60 projecting inwardly so as to hold one bearing assembly 61 between the collar 75 and sleeve 69 and the other bearing assembly 61 between the end cap 67 and sleeve 69. The bearing assemblies 61 are preferably of the tapered type so that the axial load can be safely borne. A bottom plate 73 screened securely to the conical housing 59 is provided for supporting a hook or supporting the work directly.

Since the work carrier of the present invention is ideally suited for use in a blasting operation, means are provided for sealing the bearing assemblies 61 to prevent the entry of dust and debris. The sealing means includes a collar 76 having a straight bore axially contacting the cable housing a radially extending flange portion of the conical housing 59. A tapered top 77 which is attached to the cable 45 at the upper end is adjacent the conical housing 59 at the lower end thereof so as to cover the collar 76.

The lower end of tubular shaft 27 is tapered outwardly so as to conform with the taper of the conical housing 59. As the cable 45 is raised, the conical housing 59 moves upwardly so as to engage the tapered end 79 of the shaft 27. This engagement is such that upon rotation of the shaft 27, the work engaging member 57 is also caused to rotate. To provide for a good frictional engagement between the conical housing 59 and the tapered end 79 and also provide for easy disengagement thereof, the tapered end 79 is provided with a pad 81 around the inside surface thereof to prevent wedging. This pad 81 can be of polyurethane or other suitable material. It is contemplated that triangular lancing grooves can be provided on the outside surface of conical housing 59 to prevent slippage as the work rotation system is activated. With a rigid connection being provided between the work engaging member 57 and the shaft 27, the workpiece can be rotated with the shaft 27. However, the cable 45 which is mounted to the work engaging member 57 through bearing assemblies 61 remains stationary. Therefore, twisting and undue strain on the cable 45 is prevented.

FIG. 7 illustrates in detail one embodiment of the present invention where the load up position of the hoist arrangement 47 is controlled to eliminate-excessive loads on the mounting structure. The arrangement illustrated in FIG. 7 is readily adapted to the arrangement shown in FIG. 4 by mounting the pulley 53 of FIG. 7 in the manner shown in FIG. 4. In this case, the pulley 53 is rotatably mounted at one end of member 101. The other end of member 101 is pivotably mounted on a bracket 103 which depends from a plate 105 which can be part of housing 25. The end of member 101 in which the pulley 53 is mounted is supported by a compression spring 107 connected between the member 101 and the plate 105. In a raised position the work engaging member 57 engages the end of the shaft 27 due to a winding of the cable 45 on the drum 51, the tension on the cable 45 will be transmitted to the spring 107 to cause a compression thereof and a corresponding downward movement of the pulley 53 and member 101.

Means are provided for stopping the movement of the cable 45 when the work engaging member 57 engages the tubular shaft 27. This includes a bracket 109 having a pin 111 slidably held in the vertical position. One end of the pin 111 contacts a switch- 113 mounted on member 101 in the normal hoisting position. When the work engaging member 57 is in the raised position, member 101 and the switch 113 is deflected downwardly. When this deflection reaches a predetermined point, the contact between pin 111 and switch 113 is broken causing the flow of electrical current to the motor 49 to stop. Thus the sensing means can be adjusted to prevent overload on the mounting structure. To prevent cable 45 from unwinding in the raised or load up position, an electromagnetic brake (not shown) is actuated by the sensing apparatus when the contact between pin 111 and switch 113 is broken. Other suitable means such as an override clutch ar' rangement can also be used to eliminate excessive loads on the mounting structure.

FIG. 8 illustrates another embodiment of the present invention. In this case, a boom 121 which is substantially horizontally disposed is pivotably mounted at one end on an upright frame 122. The other end of the boom 121 supports a tubular shaft 123 for rotation. A cable 125 which passes over a pulley 124 and through the shaft 123, has a work engaging member 127 rotatably connected to one end. A workpiece 129 is held by the work engaging member 127. The raising and lowering of the work is effected by power device 131. The power device 131 is shown in the form of a hydraulic or pneumatic cylinder and piston rod with the piston rod connected to one end of the cable 125 and the cylinder connected to the boom 121.

As illustrated in FIG. 8, the tubular shaft 123 includes a suitable gear 133 about the shaft 123 intermediate the ends thereof. The gear 133 is connected to a drive shaft 135 which is powered by a motor 137 with a suitable gear reduction. In this case, the means for actuating the tubular shaft 123 is mounted directly on the boom 121. With the arrangement of FIG. 8, the workpiece 129 can be moved in and out of a blast cabinet 139.

Referring to FIGS. 5 and 6, it is contemplated that any suitable hook 83 can be attached to the work engaging member 57 for lifting workpieces 85 of various sizes and shapes.The work engaging member 57 includes a loop 89 for securing a hook 83 thereto. It is contemplated that a variety of other arrangements can be utilized.

According to another embodiment of the present invention as illustrated in FIG. 6, an elongated rigid member 91 is rotatably mounted on the cable 45 and includes a key 93. The member 91 and key 93 are positioned within the tubular shaft 27. The key 93 rides in a slot or keyway in an elongated portion of the tubular shaft 27 to permit the rotation of work engaging member 57 when the shaft 27 is rotated during the raising and lowering of the workpiece 85. With this arrangement, workpiece 85 can be oscillated vertically and simultaneously rotated for better cleaning within a blasting station. The work handling apparatus of the present invention is suited for performing other treating operations such as painting, coating by dipping blowing abrasive off workpieces, etc.

In operation, the operator activates the hoist arrangement 47 or power device 131 to lower the book 83 to the workpiece 85. The workpiece 85 is attached to the hook 83 which is preferably rigid with respect to the work engaging member 57. The operator activates the hoist to raise the workpiece 85. The housing 59 being conical mates into the tapered end 79 in a raised position. The tapered junction between the conical housing 59 and tapered end 79 provide a rigid junction thereby preventing the sway of work during processing. The carrier or boom 121 then travels to a station to process the work and subsequently returns to an unloading station.

W hile preferred embodiments of the present invention have been described and illustrated herein, it is to be realized that modifications thereof may be made without departing from the broad spirit and scope of this invention as described in the appended claims.

What is claimed is:

1. A work handling apparatus comprising: a frame for supporting a workpiece; a work engaging member adapted to hold the workpiece; means on said frame for raising and lowering said work engaging member, said work engaging member being supported by said raising and lowering means for rotational movement about a substantially vertical axis; means for transmitting rota tional movement to said work engaging member, said transmitting means being supported by said frame and said raising and lowering means being adapted to move said work engaging member to a raised position to effect engagement of said work engaging member with said transmitting means to permit rotation of said work engaging member.

2. A work handling apparatus according to claim 1 wherein said frame includes a movable carriage sup ported for movement on a rail, said raising and lowering means being mounted on said carriage.

3. A work handling apparatus according to claim 1 wherein said frame includes an upright member and a boom pivotably mounted atone end to the upright member, said transmitting means being mounted on the other end of said boom.

4. A work handling apparatus according to claim 1 wherein said transmitting means includes a vertically aligned tubular shaft mounted for rotation on said frame.

5. A work handling apparatus according to claim 4 wherein said transmitting means includes means for rotating said shaft.

6. A work handling apparatus according to claim 5 wherein said means for rotating said shaft includes a gear connected to said shaft and a means for driving said gear.

7. A work handling apparatus according to claim 4 wherein said raising and lowering means includes a cable passing through said tubular shaft and said work engaging member is mounted for rotation on the lower end of said cable extending through said tubular shaft.

8. A work handling apparatus according to claim 7 wherein said raising and lowering means includes a means for drawing the cable through said shaft, said drawing means being attached to the other end of said cable.

9. A work handling apparatus according to claim 8 wherein said work engaging member includes a dependent elongated member within said tubular shaft, said elongated member being keyed to said shaft to permit rotation of the work engaging member during raisin and lowering thereof.

10. A work handling apparatus according to claim 9 including means for stopping the movement of said cable when said work engagement member. engages said tubular shaft. 

1. A work handling apparatus comprising: a frame for supporting a workpiece; a work engaging member adapted to hold the workpiece; means on said frame for raising and lowering said work engaging member, said work engaging member being supported by said raising and lowering means for rotational movement about a substantially vertical axis; means for transmitting rotational movement to said work engaging member, said transmitting means being supported by said frame and said raising and lowering means being adapted to move said work engaging member to a raised position to effect engagement of said work engaging member with said transmitting means to permit rotation of said work engaging member.
 2. A work handling apparatus according to claim 1 wherein said frame includes a movable carriage supported for movement on a rail, said raising and lowering means being mounted on said carriage.
 3. A work handling apparatus according to claim 1 wherein said frame includes an upright member and a boom pivotably mounted at one end to the upright member, said transmitting means being mounted on the other end of said boom.
 4. A work handling apparatus according to claim 1 wherein said transmitting means includes a vertically aligned tubular shaft mounted for rotation on said frame.
 5. A work handling apparatus according to claim 4 wherein said transmitting means includes means for rotating said shaft.
 6. A work handling apparatus according to claim 5 wherein said means for rotating said shaft includes a gear connected to said shaft and a means for driving said gear.
 7. A work handling apparatus according to claim 4 wherein said raising and lowering means includes a cable passing through said tubular shaft and said work engaging member is mounted for rotation on the lower end of said cable extending through said tubular shaft.
 8. A work handling apparatus according to claim 7 wherein said raising and lowering means includes a means for drawing the cable through said shaft, said drawing means being attached to the other end of said cable.
 9. A work handling apparatus according to claim 8 wherein said work engaging member includes a dependent elongated member within said tubular shaft, said elongated member being Keyed to said shaft to permit rotation of the work engaging member during raising and lowering thereof.
 10. A work handling apparatus according to claim 9 including means for stopping the movement of said cable when said work engagement member engages said tubular shaft. 